I don't like taxes either, but as far as I know, most Bitcoin users aren't anarchists, they are Libertarians (I'm a moderate Libertarian), so why not pay the tax? The government may be to large, but you are still getting a service and need to pay what you owe.
Very few libertarians support transaction taxes like income/sales/gift, instead sometimes favoring either donations, pigovian taxes, natural resource taxes, or property taxes. Even summarizing it that much doesn't represent everyone, it's like herding cats.
In the end, being moderate libertarian is like being a little pregnant. Something is either moral or immoral. If you think the idea of gov is morally okay, then how do you draw the line between gov and non-gov? And why the government cannot be absolute? Why democratic majority cannot kill minority? Why certain actions on part of some people are evil (theft, threat of murder), but on part of others are moral (taxation, arrests)?
For me at least, the difference is pragmatism. I'm open to the idea of anarchy but I'm open to nuclear experimentation too. Makes sense in theory, could be great, but let's test it somewhere that isn't my home.